Using PGP Signatures for Securing SIP Infrastructures
Because of increasing bandwidth and decreasing costs for the provider, Voice-over-IP is an alternative to the Public Switched Telephone Network for many users. But with the propagation of Voice-over-IP new harassments and threats occur. Assuring the identity of communication partners is significant in this context. Without the authentication of communication partners, the infrastructure is vulnerable to attacks like URI-spoofing, call and registration hijacking. Authenticity is necessary for detecting and avoiding SPam over Internet Telephony (SPIT). Only if the identity of a caller can be verified, a source of SPIT can be exposed and appropriate countermeasures can be taken.